Numerous randomized trials and observational studies have found that Roux-en-Y gastric bypass, adjustable gastric banding, and vertical sleeve gastrectomy cause dramatic weight loss and improved control of many chronic conditions. As a result, rates of bariatric surgery have increased over the past two decades. Bariatric surgery has short term benefits but less is known about long-term outcomes, particularly mental health outcomes. Emerging evidence suggests that bariatric surgery may induce new onset opioid use disorder (OUD) or alcohol misuse (AM) and exacerbate existing AM or OUD. Obese people have greater rates of AM than overweight and normal weight people and AM appears to worsen two years after surgery. Obese people also have greater rates of depression, which appears to decrease 1-2 years after surgery. Bariatric surgery may have adverse effects on OUD and AM in the short term, but almost nothing is known about these outcomes 5 years after bariatric surgery, because the few studies examining these outcomes were limited to 1- 2 year follow-up of predominantly non-US surgical cohorts and lacked non-surgical patients to account for regression to the mean. There is also a major evidence gap for AM, prescription opioid misuse or depression after bariatric surgery in men or older patients because the few studies examining these outcomes were mostly comprised of younger female patients. Further, there is no evidence whether these issues moderate the effect of surgery on weight change beyond 3 years. We have conducted several studies of veterans' outcomes following bariatric surgery. Building on our experience with matched cohorts of 2,257 veterans undergoing bariatric surgery in 2002-2011 and >7,000 non- surgical controls, we propose to address critical evidence gaps about 5-year post-surgical rates of AM, OUD and depression treatment in four specific aims: Aim 1: Examine long-term trends in the prevalence of AM (based on a validated screen) among bariatric surgery patients and matched non-surgical patients with and without a history of recognized AM. Aim 2: Examine long-term change in prescription opioid misuse among bariatric surgery patients and matched patients with and without opioid misuse at baseline. Aim 3: Examine long-term rates of depression treatment among bariatric surgery patients and matched patients with and without depression treatment at baseline. Aim 4: Examine whether baseline AM, prescription opioid use, and depression treatment moderate the effect of bariatric surgery on long-term weight change. Secondary Aim: Examine whether long-term changes in AM, prescription opioid use and depression treatment after surgery differ by patients undergoing RYGB, AGB or VSG.